The Angel was a being of great power connected to the Omega Comet.
When the Omega Comet came near Earth, the Voltron force had to take out the rings around it. Roy Fokker in his Skull-One and Voltron took out the rings from both sides of it. When Roy is pulled toward the Comet by its intense gravity, a bright Angel appeared, and offers to take Roy to the end of the Universe if he will follow it. Roy says that all he wants is Rick and Claudia back. Voltron fired the Blazing Bow at it, which returned their realities to normal. (Robotech/Voltron 5)